Share-Based Compensation - Schedule of Stock Options Outstanding and Exercisable (Detail)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding (in shares) | shares	678,000
Options Exercisable, Shares | shares	605,000
$26.68-$33.95
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, minimum (in dollars per share)	$ 26.68
Exercise Price Range, maximum (in dollars per share)	$ 33.95
Options Outstanding (in shares) | shares	137,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 31.46
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	3 years 8 months 12 days
Options Exercisable, Shares | shares	124,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 31.53
$34.33-$34.62
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, minimum (in dollars per share)	34.33
Exercise Price Range, maximum (in dollars per share)	$ 34.62
Options Outstanding (in shares) | shares	138,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 34.40
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	5 years 4 months 24 days
Options Exercisable, Shares | shares	138,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 34.40
$35.73-$36.87
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, minimum (in dollars per share)	35.73
Exercise Price Range, maximum (in dollars per share)	$ 36.87
Options Outstanding (in shares) | shares	195,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 36.67
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	4 years 4 months 24 days
Options Exercisable, Shares | shares	188,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 36.68
$36.89-$40.36
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, minimum (in dollars per share)	36.89
Exercise Price Range, maximum (in dollars per share)	$ 40.36
Options Outstanding (in shares) | shares	202,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 39.28
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	5 years 4 months 24 days
Options Exercisable, Shares | shares	149,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 39.12
$41.69-$41.69
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, minimum (in dollars per share)	41.69
Exercise Price Range, maximum (in dollars per share)	$ 41.69
Options Outstanding (in shares) | shares	6,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 41.69
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	3 months 18 days
Options Exercisable, Shares | shares	6,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 41.69